I'd say it would probably be the sealing off of the trunk the way it was done... both deck lid and around the face of the sub, the porting it through the rear deck.. essentially the sub's front and back waves are completely seperated, and the sub itself is completely sealed off from the trunk... essentially it is sitting in the cab of the car.
this lead to ZERO, and I mean it vibrations in the trunk. and as a bonus it quieted the exhaust. But I'd have to say that the enclosures and dynamatting of the doors is also really impressive as well. my car is running with an open downpipe right now, and its not even close to being as loud as it is outside the car.
this lead to ZERO, and I mean it vibrations in the trunk. and as a bonus it quieted the exhaust. But I'd have to say that the enclosures and dynamatting of the doors is also really impressive as well. my car is running with an open downpipe right now, and its not even close to being as loud as it is outside the car.